18 April 2000  

Dear editor,

Kathy Fulcher's article on chronic fatigue syndrome (CFS) had a clear message, but as a medical archivist, I was disturbed by her selective use of information and biased interpretation of the research¹.

For instance, Fulcher began by listing the Oxford guidelines to diagnose CFS. This surprised me, since they were rejected six years ago by an International group of experts who questioned their validity and specificity². In practice, patients who meet the Oxford guidelines show substantial similarities to groups suffering from depression, phobias and somatisation. Conversely, people selected using the International criteria more closely resemble patients with neurological or immunological disorders^3,4.

Also noteworthy is Fulcher's emphasis on fatigue. I can see how deconditioning and depression might perpetuate tiredness and reduce physical function, but how do they explain sore throats, swollen glands, visual disturbances and an intolerance to alcohol?

Also missing from Fulcher's account is the mass of evidence which does not support the deconditioning theory, or the use of cognitive behaviour therapy (CBT) and graded exercise^3,5.6. For example, she didn't mention the fact that the majority of patients with CFS remain ambulant, that they do not resort to prolonged or excessive rest and that few show outward signs of immobility such as muscle wastage^7,8. Indeed, since most patients operate at or near their activity ceiling, graded exercise is not only inappropriate but may actually exacerbate fatigue^3,6,9.

However, the most compelling evidence against Fulcher's theory comes from studies which actually measured the activity levels of people with CFS. One of these found that people with CFS were no more inactive than patients with mild/moderate multiple sclerosis⁷. A second reported that the reduction in activity following exercise was limited and that most patients coped using the strategy of pacing, not avoidance⁸. In fact, only the most severely affected or those suffering from psychological disorders appear to show the kind of behaviour described by Fulcher. Three quarters of this population don't (Bazelmans et al. Unpublished).

Aside from the research evidence, there are also common sense  arguments against Fulcher's explanation for CFS. Firstly, people who are forced to take bed rest or lead sedentary lives (e.g. following a broken leg, some prisoners) are not at an increased risk. If inactivity was an important cause of the illness, they should be. Secondly, about a third of people who take part in studies on CFS continue to work. Although the extent of their 'avoidance behaviour' must be limited, they report the same symptom complex as those who stay at home.  Thirdly, the theory implies that inactivity and maladaptive beliefs cause exactly the same symptoms as the initial infection or event which triggered the CFS.  If this is true, when does the switch occur and why don't the patients notice this?

Finally, here is some of the information which Fulcher overlooked in her discussion on CBT. She was correct in noting that 73% of the patients in one trial improved on the Karnofsky (disability) scale, compared with 27% of the people receiving standard care¹⁰. However, readers may not know that improvement was defined as reaching 80 on that scale or an increase of just ten points. Nor do they probably know that the scores at baseline ranged from 60 to 78, and that the median was 72. In other words, this was not a severely disabled group and some were only two points away from a 'successful' outcome.

Readers should also take into account that the two groups weren't evenly matched. Thus before treatment, the patients due to be given CBT spent much more time in bed compared to the controls (3.3 days per week versus 1.6). Moreover, only 13% of the CBT group were working at baseline compared to 50% of the controls.

As far as the results are concerned, it's worth noting that at the 8 months follow-up, the treated group were still spending 1.8 days in bed, just exceeding the 1.6 days reported by the controls. Regarding work status, 63% of the treated patients showed an improvement compared to only 20% of the controls. However, if these figures refer to people returning to employment, 77% of the CBT group were working at the final follow-up, compared to 70% of the controls. Is that really impressive?

In her summary of her own trial¹¹, Fulcher again accentuated the positive and simply ignored the negative. It's true that 55% of her patients rated themselves as 'better' or 'very much better' following graded exercise.  However, the others reported little if any change and since the mean score for fatigue was 20.6 on a scale where 14 indicates 'normal', many clearly remained unwell.

An objective, evidence-based assessment would have concluded that CBT and/or graded exercise is only helpful for patients whose fatigue is complicated by depression, phobic avoidance or irrational beliefs. Since there have been no published reports of successful trials on patients with post-infectious fatigue, and there are two reports to the contrary, a claim that CBT and/or graded exercise is effective for everyone with CFS seems somewhat premature.

In my view, biased articles on medical matters mislead practitioners and undermine clinical care. This wouldn't be acceptable if we were discussing cancer or MS. It shouldn't be acceptable in relation to CFS.

Yours faithfully,

Ellen Goudsmit PhD C.Psychol.

1. Fulcher, K (2000) Physical activity and chronic fatigue syndrome. SportEX. March: 11-15.

2. Fukuda K, Straus SE, Hickie I, Sharpe MC, Dobbins JG, Komaroff, A and the International Chronic Fatigue Syndrome Study Group. (1994). The chronic fatigue syndrome: a comprehensive approach to its definition and study.  Ann Int Med, 121: 953-959.

3. Friedberg, F (1999).  A subgroup analysis of cognitive-behavioral treatment studies. Journal of Chronic Fatigue Syndrome, 5, 3/4: 149-159.

4. Landay AL, Jessop, C, Lennette ET and Levy JA (1991). Chronic fatigue syndrome: clinical condition associated with immune activation. Lancet, 338: 707-712.

5. Lloyd AR, Hickie I, Brockman A, Hickie C, Wilson A et al (1993).  Immunologic and psychologic therapy for patients with chronic fatigue syndrome: a double-blind, placebo-controlled trial. Am J Med, 94: 197-203.

6. Friedberg, F and Krupp, LB (1994).  A comparison of cognitive behavioral treatment for chronic fatigue syndrome and primary depression.  Clin Infect Dis, 18, (suppl 1): S105-S110.

7. Vercoulen JHMM, Bazelmans E, Swanink CMA, Fennis JFM, Galama JMD, Jongen PJH et al (1997). Physical activity in chronic fatigue syndrome: assessment and its role in fatigue.  J Psychiatr Res, 31: 661-673.

8. Sisto SA, Tapp WN, LaManca JJ, Ling W, Korn LR et al (1998). Physical activity  before and after exercise in women with chronic fatigue syndrome. Q J Med, 91: 465-473.

9. Lapp, C (1997).  Exercise limits in chronic fatigue syndrome. Am J Med, 103: 83-84.

10. Sharpe M, Hawton K, Simkin S, Surawy C, Hackmann A et al (1996). Cognitive behaviour therapy for the chronic fatigue syndrome: a randomised controlled trial. BMJ, 312: 22-26.

11. Fulcher KY and White PD. Randomized controlled trial of graded exercise in patients with the chronic fatigue syndrome (1997). BMJ, 314: 1647-1652.